Abrasive system and method of using the same

ABSTRACT

An abrading system is presented. The system includes a first vibratory structure comprising a first plurality of protrusions. The system also includes a second vibratory structure comprising a second plurality of protrusions. The system also includes an abrasive article contacting the first film. The system also includes a stroke plate coupled to the second film. When the stroke plate is activated, the first and second plurality of protrusions are configured to interlock and slip with respect to each other in a first direction.

BACKGROUND

For years, a class of abrasive articles known generically as “structuredabrasive articles” has been sold commercially for use in surfacefinishing. Structured abrasive articles have a structured abrasive layeraffixed to a backing, and are typically used in conjunction with aliquid such as, for example, water, optionally containing surfactant.The structured abrasive layer has a plurality of shaped abrasivecomposites (typically having minute size), each having abrasiveparticles dispersed a binder. In many cases, the shaped abrasivecomposites are precisely shaped, for example, according to variousgeometric shapes (e.g., pyramids). Examples of such structured abrasivearticles include those marketed under the trade designation “TRIZACT” by3M Company, St. Paul, Minnesota.

Structured abrasive articles are often used in combination with a backuppad mounted to a tool (e.g., a disk sander or a random orbit sander). Insuch applications, structured abrasive articles typically have anattachment interface layer (e.g., a hooked film, looped fabric, oradhesive) that affixes them to the back up pad during use.

SUMMARY

An abrading system is presented. The system includes a first vibratorystructure comprising a first plurality of protrusions. The system alsoincludes a second vibratory structure comprising a second plurality ofprotrusions. The system also includes an abrasive article contacting thefirst film. The system also includes a stroke plate coupled to thesecond film. When the stroke plate is activated, the first and secondplurality of protrusions are configured to interlock and slip withrespect to each other in a first direction.

Systems provided herein provide vibration to an abrasive article duringan abrading operation, which increases the abrading efficiency andallows for a larger surface area to be used during a sanding operationthan was available in previous systems.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a schematic view showing the configuration of a superfinishing apparatus.

FIGS. 2A-2C illustrate schematic views of a linear vibratory finishingapparatus in accordance with embodiments herein.

FIGS. 3A-3D illustrate schematic views of microreplicated filmstructures in accordance with embodiments herein.

FIG. 4 illustrates a method of abrading a workpiece in accordance withembodiments herein.

FIGS. 5A-5C illustrate images of a linear vibratory finishing system inaccordance with embodiments herein.

FIGS. 6A-6B illustrates vibratory finishing systems in accordance withembodiments herein.

FIGS. 7A-7C illustrate experimental results discussed in the Examplesherein.

DETAILED DESCRIPTION

FIG. 1 is a schematic view showing the configuration of a superfinishing apparatus. An abrasive material product 11 is fed out of afeeding roll 12 and wound up on a rolling roll 14 via a contact roll 13.The contact roll is pushed to the outer circumferential face of thecylindrical work piece 16 by an air cylinder 15. While the cylindricalwork piece 16 is rotated in the direction of the arrow, the abrasivematerial product is fed to the direction opposed to the direction ofmovement of the object face to be abraded to carry out abrading.

Currently, robotic sanders utilize abrasive discs for abrasiveoperations. However, it is difficult to determine when an abrasive discneeds to be replaced, and the actual method of replacement iscomplicated. Customers desire abrasive systems where the cuttingperformance is consistent over the life of the abrasive article, andthat the life of the abrasive article be long, to reduce the frequency,and associated difficulty, with changing out abrasive articles for arobot repair.

Contact-wheel based sanding systems present an alternative to sandingdisc systems, as they can be used in a role-to-role system and allow fora long abrasive life. Contact-wheel based systems have a small contactarea which can result in an applied unit pressure become too high apressure for a given operation. As more and more sanding and finishingoperations are moving to robotic solutions, it is required that a systembe compliant for surfaces that have curvature. Additionally, to allowfor grinding by vibration, a system must have a holding method thatallows for slippage in the direction of the feed and does not slip inthe cross-direction of the feed. Although feed sanding units usingcontact-wheel in the sanding section, like the example of FIG. 1 , therehave been no feed sanding units with large flat sanding sections using asoft material.

Conventional contact wheels are not soft or flexible, which is anecessary feature for finishing surfaces with curvature or curvedsurfaces. Soft contact wheels are not ideal because when the wheeldeforms, the soft sheet wrinkles, preventing satisfactory polishingperformance. In contrast, contact wheels cannot deform, which presentsdifficulty in finishing curved surfaces, like a hood of a car.

A system utilizing a soft, flexible and deformable abrasive article isdesired, to handle curvature of surfaces. Additionally, a flat padoffers a larger and wider surface area. The deformation will have asmaller impact on the area of the flat pad in contact with the surfacebecause of the softness of the article.

As used herein, the term “soft,” with respect to an abrasive pad, isdefined by JIS K 7312. The C hardness means hardness immediately after apressing surface is in close contact by a testing method specified in“Spring Hardness Test Type C Testing Method” in an appendix 2 in JISK7312: 1996. This testing method uses a spring hardness testing machinehaving a structure that indicates a distance of an indenter protrudingfrom a hole at a center of the pressing surface by spring pressure beingpressed to return by a test specimen when the pressing surface of thetesting machine is brought into close contact with a surface of the testspecimen by scale as the hardness. The measured surface of the testspecimen has a size at least equal to or more than the pressing surfaceof the testing machine. In some embodiments, the C hardness of padsdescribed herein is as low as about 5, or as low as about 10, or as lowas about 15, or as low as about 20, or as low as about 25, or as low asabout 30.

The pads described herein may be used in either a continuous feed or anintermittent feed method. In a continuous feed setup, dynamic frictionis created. Therefore, the system may result in lower polishingperformance and/or require equipment with stronger feeding power.

In an intermittent feed set up, dynamic friction is also produced,however static friction is also produced in the cross direction. Thefriction is higher stable in the cross direction, but the friction cankeep the feed direction smooth.

Systems and methods herein can use a roll-to-roll feeding system ineither a continuous or intermediate feed operation, which presents animprovement over disc-changing systems previously used for manyfinishing operations. This increases efficiency with the reduceddowntime required to change discs. Additionally, disc-changing systemsusually see decreased cutting over time. The ability to use a roll ofabrasive material results in more stable cut rates over tame, and canresult in a long use-life based on the length of the roll. And withrespect to existing roll-to-roll systems, the systems and methodsdescribed herein allow for a wider surface to be available for anabrading operation, with the benefit of a softer material which allowsfor abrading curved surfaces.

FIGS. 2A-2C illustrate schematic views of a linear vibratory finishingapparatus in accordance with embodiments herein. FIG. 2A illustrates aperspective view of a linear vibratory finishing apparatus 100 thatincludes a stroke plate 110 which actuates vibratory abrasive system150, which abrades a surface of workpiece 130. As illustrated in theside view 102 of FIG. 2B, in some embodiments a cushion 120, or pad maybe present between stroke plate 110 and vibratory system 150. Cushion120 may serve to increase and even out an applied pressure across arectangular surface area of workpiece 130. The surface area may besubstantially the width of an abrasive article, such as abrasive belt156, and may have a length as long as stroke plate 110, in someembodiments. Cushion 120 is a soft material allowing for the appliedpressure to spread across a curved surface.

FIG. 2C is an enlarged cutaway view 104, which more clearly shows thecomponents of a vibratory system 150 in an embodiment herein. In oneembodiment, a first structure 152 is coupled to a stroke plate, eitherdirectly or through a cushion 120. First structure 152 is shaped tointerlock with corresponding features of a second structure 154, whichcontacts an abrasive article 156. For example, abrasive article 156 maybe a seamless abrasive belt fed under tension through system 100, or mayotherwise be a long abrasive article fed from roll-to-roll. Abrasivearticle 156 may be a coated abrasive article, a nonwoven abrasivearticle, or a bonded abrasive article. Abrasive article 156 may comprisecrushed abrasive particles, formed abrasive particles, shaped abrasiveparticles, and/or agglomerates, composites or mixtures thereof. Abrasivearticle 156, as illustrated in FIG. 2C, contacts and abrades a surfaceof workpiece 130.

In some embodiments, first and second structure 152, 154 each include arepeating pattern of substructures that interlock as illustrated in FIG.2C. The repeating pattern of substructures may include evenly spacedprotrusions, alternating hills and valleys, or a more complex structure,such as the varying heights of teeth on a key.

In some embodiments, first and second structures 152, 154, are evenlystreaked microreplicated structures. Such a configuration may bettercause vibrations to be transmitted mechanically during feeding as thefirst and second structures 152, 154 mesh and interlock like teeth ongears. non-evenly streaked micro-replicated structures may was dynamicfriction that does not transmit vibration sufficiently.

In some embodiments, first and second structures 152, 154 are formedfrom micro-replicated film. In some embodiments, the microreplicatedfilm is made from a resin with flexibility and lubricity is preferableas long as the strength can be secured. For example, a polyolefin filmmade be used.

Use of micro-replicated film structures 152, 154 facilitates sanding ofa larger surface area that was not previously possible using systemssuch as that illustrated in FIG. 1 , which provides abrading only alongthe contact point between roll 13 and surface 16.

Referring back to FIG. 1 , for example, if a contact wheel has adiameter of about 50 mm, a contact angle of about 60° is required tosecure the frictional force. In order for the contact to follow a curvedsurface with the diameter and contact angle, the abrasive article 11must be elastic. However, handling stretch web is difficult. Incontrast, using a pad with film structures 152, 154, over a largesurface area, the expansion and contraction is slight even following acurved surface. While the system illustrated in FIGS. 2A-2C can polish aflat surface, it presents an improved ability over prior art systems tofollow curved surfaces. Cushion 120 compensates, improving the abilityto manage curved surfaces. FIGS. 3A-3C illustrate schematic views ofmicroreplicated film structures in accordance with embodiments herein.As described with respect to FIG. 2 , in some embodiments a vibratorysystem includes a first structure 210 and a second structure 220 thatallow for movement, or slippage, along a first direction 234, but nosubstantial slippage in a second direction 232. Slippage may befacilitated by the fitting 230 between first and second structures 210,220. In some embodiments, fitting 230 may include a gap allowing forfreedom of movement.

Structure 210, in some embodiment, includes a plurality of protrusions212 extending from a backing 214. In some embodiments, protrusions 212are substantially identical in height and width and spacing betweenadjoining protrusions. In some embodiments, protrusions 212 are of thesame material as backing 214. Protrusions 212 may be coextruded, orconformed with backing 214.

Structure 220, in some embodiment, includes a plurality of protrusions222 extending from a backing 224. In some embodiments, protrusions 222are substantially identical in height and width and spacing betweenadjoining protrusions. In some embodiments, protrusions 222 are of thesame material as backing 224. Protrusions 222 may be coextruded, orconformed with backing 224.

In some embodiments, fitting 230 does not include a gap, and structure210 is substantially identical in that dimensions of protrusions 212 areidentical to dimensions of protrusions 222. As illustrated in FIG. 3A,each of structures 210, 220 are defined by a width 238 and a length 236.Slippage between structures 210, 220 occurs substantially only indirection 234, along the width.

While FIGS. 3A and 3B illustrate substantially rectangular protrusions212, 222 with rounded edges, it is expressly contemplated that othermicro-replicated structures are possible, as illustrated in thecomparison between FIGS. 3C and 3D.

FIG. 3C illustrates a view 250 of a pair of protrusions 260 extendingfrom a support structure. Each of protrusions 260 is identical, having aheight 256 extending from the base, a width 252, where width issubstantially perpendicular to height 256, in the embodiment illustratedin FIG. 3C. Protrusions 260 are substantially rectangular in shape, withrounded edges. However, other shapes, including a greater degree ofrounding, sharp corners are also explicitly envisioned. As illustratedin FIG. 3C, height 256 of protrusions 260 is a height of the protrusiononly, and does not include a thickness of base 258 of structure 250.

In some embodiments, thickness 258 is sufficient to allow for stabilityof structure 250, but thin enough to allow for some flexibility instructure 250 as protrusions 260 vibrate.

Protrusions 260 are spaced apart from each other by space 254. Asillustrated in FIG. 2C, in some embodiments, space 254 is greater thanwidth 252, which allows for room for protrusions 260 to vibrate when inan interlocking position. In some embodiments, therefore, width 252 isless than or equal to spacing 254. Additionally, in some embodiments,the combination of spacing 254 and width 252 is less than twice height256, as illustrated in Equation 1 below:

(width 252+spacing 254)<(2×height 256)  Equation 1

In addition to providing slip prevention, referring to FIG. 3D, if thepitch is large relative to the height, the force per pitch increases.Since it is gentle, lateral slippage is more likely to occur. The valuethat can secure an angle of about 45° is limited to bout 2:1. FIG. 3Dillustrates another configuration for protrusions 280 extending from astructure 270 with base thickness 278. Protrusions 280 have a height 276and a total repeating width of first width 272 and second width 274. Insome embodiments, the triangular-shaped protrusions 280 are isoscelestriangles, such that widths 272 and 274 are the same. In otherembodiments, protrusions 280 are scalene triangles, such that widths 272and 274 are different from each other and from a total width ofprotrusion 280. Additionally, while widths 272 and 274 are presentedsuch that no spacing (comparable to spacing 254) is present betweenadjoining protrusions, such an embodiment is expressly contemplated.

FIG. 3D illustrates an embodiment where protrusions 280 have sharpcorners both at their tips and where adjoining protrusions touch.However, in other embodiments, these may be rounded. In an extremeembodiment, protrusions 280 are rounded to the point of resembling sineor cosine waves.

Additionally, in some embodiments, the combination of width 254 andwidth 252 is less than twice height 256, as illustrated in Equation 2below:

(width 272+width 274)<(2×height 276)  Equation 2

FIG. 4 illustrates a method of abrading a workpiece in accordance withembodiments herein.

In block 310, an abrasive article is coupled to a vibratory system. Thevibratory system, in some embodiments, includes a vibration source, anabrasive feed source, and a vibration assembly. The vibration assemblymay include, as described above with respect to FIGS. 2A-2C, opposingstructures may be placed in interlocking positions 316 with respect toeach other, and the abrasive article may be interact with only one ofthe structures, on a side opposite the plurality of protrusions.

Abrasive article may be moveably coupled to vibratory system, asindicated in block 312. For example, the abrasive article may be aseamless belt that is fed through the vibratory system such that asurface area of the abrasive article in contact with a workpiece isconstantly, or frequently, changing during an abrasive operation. Thismay include abrasive article being in a non-fixed position, as indicatedin block 314, with respect to the vibratory system. However, otherconfigurations 318 are possible. For example, the abrasive article maybe a coated abrasive article that is fixed to the vibratory system, forexample using a hook and loop or adhesive-based coupling.

In block 320, a workpiece is abraded. The workpiece is abraded using asurface area 332 of the abrasive article in contact with the workpiece.In contrast with previous systems, such as that illustrated in FIG. 1 ,a square or rectangular surface area of an abrasive article is availableduring an abrading operation, resulting in a greater area being abradedat any given time, speeding up an abrasive operation. For example, alength and width of an abrasive area may be similar, in contrast toprevious systems, such as that of FIG. 1 , where the length and width ofan abrading operation may differ by a factor of 5 or 10 or more.

Either the abrasive article or the workpiece may be fed through thevibratory system as a linear feed 334. For example, the abrasive articlemay be a seamless belt fed through the system, as illustrated in theexample of FIGS. 5 and 6 , presented below. Alternatively, the abrasivearticle may be a coated abrasive article and the workpiece may be fedthrough the vibratory system. However, in other embodiments 336, thevibratory system is moved with respect to a workpiece, as described withrespect to the robotic repair unit embodiment of FIG. 6 , discussedbelow.

The vibratory system, in some embodiments, vibrates during an abradingoperation. The vibration may be caused by stroke plate movement 332,movement of a coupler 324, or through another movement mechanism 326.

FIGS. 5A-5C illustrate images of a linear vibratory finishing system inaccordance with embodiments herein. FIG. 5A illustrates a view of asystem 500, illustrating stroke directionality 510, and feed direction520. In some embodiments, a stroke plate can facilitate vibration atrates at least as high as 30 strokes/min, or at least as high as 100strokes/minute, or at least as high as 500 strokes/minute, or at leastas high as 1000 strokes/minute, or at least as high as 5000 strokes/min,or at least as high as 8000 strokes/minute, or at least as high as10,000 strokes/minute, or at least as high as 12,000 strokes/minute, orat least as high as 15,000 strokes/min. When the stroke is long, thenumber of strokes is small, and when the stroke is short, the number ofstrokes is large.

The system 500 is designed to receive an abrasive belt moving at a feedrate, in feed direction 520, at a rate of at least 1 mm/min, at least 10mm/min, at least 20 mm/min, at least 50 mm/min, at least 100 mm/min, atleast 150 mm/min or as high as 200 mm/min. The higher the number ofstrokes, the higher the feed rate, and the smaller the stroke, the lowerthe feed rate.

FIG. 5B illustrates a view of system 500 with an abrasive article 530 inplace. As illustrated in FIG. 5B, in one embodiment, abrasive article isfed linearly through system 500. In some embodiments, an entire width532, or substantially an entire width is available for use within system500, allowing for a larger surface area 534 to be used during anabrading operation at a time. FIG. 5C illustrates a closer view of thefeed area of system 500, including a workpiece 540.

FIGS. 6A and 6B illustrates vibratory finishing systems in accordancewith embodiments herein. FIG. 6A illustrates a robotic repair mountedfinishing system 600 that includes a vibratory finishing system 620mounted to a robotic repair unit 610. Robotic repair unit 610 canautomatically move finishing system 620 into place above a workpieceneeding finishing work.

Vibratory finishing system 620 includes a vibratory system 622, whichmay include a compressible cushion that allows system 620 to providefinishing to surfaces with curvature, such as automobile hoods, doors,etc. System 622 also includes interlocking structures, such as thosedescribed with respect to FIGS. 2-3 , positioned in between abrasivearticle 630 and stroke plate 626 such that slippage can occur in thedirection perpendicular to the movement of abrasive article 630, e.g.into and out of the plane of view of FIG. 6A. Abrasive article 630, inthe embodiment of FIG. 6A, is a belt that moves from one of rolls 624 tothe other during an abrasive operation. The abrasive article 630 isstabilized by guides 628 which ensure that that abrasive article 630 isheld tightly against vibration system 622. This may be helpful to ensurethat while the interlocking structures can move into and out of theplane of FIG. 6A, they do not have enough free movement to fall out ofalignment. Abrasive article 630 is maintained under tension duringoperation.

As described with respect to FIGS. 2-3 , vibratory system 622 includesan upper and lower structure, with interlocking features that behavelike gear teeth, allowing for movement in a single direction, e.g. intoand out of the plane of FIG. 6A, but not in the direction of movement ofabrasive article 630.

An alternative system 650 is illustrated in FIG. 6B. System 650 may alsobe mountable to a robotic repair unit, or may operate independently. Asillustrated in FIG. 6B, an abrasive article 660 is fed from a first roll652 to a second roll 654, under tension provided by guides 656.

A vibratory system 680 is provided that, as discussed above, includes afirst and second interlocking structures that allow for slippage indirection 682, e.g. into and out of the plane of FIG. 6B. Vibratorysystem 680 may also include a cushion that ensures a surface area 684 ofworksurface 670 is in contact with abrasive article 660 during anentirety of an abrasive operation.

Abrasive articles as described herein can be formed of any suitablematerial and can include any suitable abrasive particles. Suitablebackings include, for example, polymeric films (including primedpolymeric film), cloth, paper, foraminous and non-foraminous polymericfoam, vulcanized fiber, fiber reinforced thermoplastic backing, meltspunor meltblown nonwovens, treated versions thereof (e.g., with awaterproofing treatment), and combinations thereof. Suitablethermoplastic polymers for use in polymeric films include, for example,polyolefins (e.g., polyethylene, and polypropylene), polyesters (e.g.,polyethylene terephthalate), polyamides (e.g., nylon-6 and nylon-6,6),polyimides, polycarbonates, blends thereof, and combinations thereof.

Typically, at least one major surface of the backing is smooth (forexample, to serve as the first major surface).

The backing may contain various additive(s). Examples of suitableadditives include colorants, processing aids, reinforcing fibers, heatstabilizers, UV stabilizers, and antioxidants. Examples of usefulfillers include clays, calcium carbonate, glass beads, talc, clays,mica, wood flour; and carbon black. In some embodiments, the backing maybe a composite film such as, for example, a coextruded film having twoor more discrete layers.

The abrasives particles may include particles of any suitable shape andcomposition, including crushed abrasive particles, formed abrasiveparticles, precision shaped abrasive particles; and/or agglomerates,mixtures or composites thereof.

Examples of suitable abrasive particles for first and/or second sets ofabrasive particles include: fused aluminum oxide; heat-treated aluminumoxide; white fused aluminum oxide; ceramic aluminum oxide materials suchas those commercially available under the trade designation 3M CERAMICABRASIVE GRAIN from 3M Company, St. Paul, MN; brown aluminum oxide; bluealuminum oxide; silicon carbide (including green silicon carbide);titanium diboride; boron carbide; tungsten carbide; garnet; titaniumcarbide; diamond; cubic boron nitride; garnet; fused alumina zirconia;iron oxide; chromia; zirconia; titania; tin oxide; quartz; feldspar;flint; emery; sol-gel-derived abrasive particles; and combinationsthereof. Of these, molded sol-gel derived alpha alumina abrasiveparticles are preferred in many embodiments. Abrasive material thatcannot be processed by a sol-gel route may be molded with a temporary orpermanent binder to form shaped precursor particles which are thensintered to form shaped abrasive particles, for example, as described inU. S. Pat. Appln. Publ. No. 2016/0068729 A1 (Erickson et al.).

Examples of sol-gel-derived abrasive particles and methods for theirpreparation can be found in U.S. Pat. No. 4,314,827 (Leitheiser et al.);U.S. Pat. No. 4,623,364 (Cottringer et al.); U.S. Pat. No. 4,744,802(Schwabel), U.S. Pat. No. 4,770,671 (Monroe et al.); and U.S. Pat. No.4,881,951 (Monroe et al.). It is also contemplated that the abrasiveparticles could include abrasive agglomerates such, for example, asthose described in U.S. Pat. No. 4,652,275 (Bloecher et al.) or U.S.Pat. No. 4,799,939 (Bloecher et al.). In some embodiments, first and/orabrasive particles may be surface-treated with a coupling agent (e.g.,an organosilane coupling agent) or other physical treatment (e.g., ironoxide or titanium oxide) to enhance adhesion of the abrasive particlesto the binder (e.g., make and/or size layer). The abrasive particles maybe treated before combining them with the corresponding binderprecursor, or they may be surface treated in situ by including acoupling agent to the binder.

Preferably, first and/or second abrasive particles are ceramic abrasiveparticles such as, for example, sol-gel-derived polycrystalline alphaalumina particles. Abrasive particles composed of crystallites of alphaalumina, magnesium alumina spinel, and a rare earth hexagonal aluminatemay be prepared using sol-gel precursor alpha alumina particlesaccording to methods described in, for example, U.S. Pat. No. 5,213,591(Celikkaya et al.) and U. S. Pat. Appln. Publ. Nos. 2009/0165394 A1(Culler et al.) and 2009/0169816 A1 (Erickson et al.).

Alpha alumina-based triangular abrasive particles can be made accordingto well-known multistep processes. Briefly, the method includes thesteps of making either a seeded or non-seeded sol-gel alpha aluminaprecursor dispersion that can be converted into alpha alumina; fillingone or more mold cavities having the desired outer shape of the abrasiveparticle with the sol-gel, drying the sol-gel to form precursortriangular abrasive particles; removing the precursor abrasive particlesfrom the mold cavities; calcining the precursor abrasive particles toform calcined, precursor abrasive particles, and then sintering thecalcined, precursor abrasive particles to form the first and/or secondset of abrasive particles. The process will now be described in greaterdetail.

Further details concerning methods of making sol-gel-derived abrasiveparticles can be found in, for example, U.S. Pat. No. 4,314,827(Leitheiser); U.S. Pat. No. 5,152,917 (Pieper et al.); U.S. Pat. No.5,435,816 (Spurgeon et al.); U.S. Pat. No. 5,672,097 (Hoopman et al.);U.S. Pat. No. 5,946,991 (Hoopman et al.); U.S. Pat. No. 5,975,987(Hoopman et al.); and U.S. Pat. No. 6,129,540 (Hoopman et al.); and inU. S. Publ. Pat. Appln. No. 2009/0165394 A1 (Culler et al.).

In some preferred embodiments, the abrasive particles areprecisely-shaped in that individual abrasive particles will have a shapethat is essentially the shape of the portion of the cavity of a mold orproduction tool in which the particle precursor was dried, prior tooptional calcining and sintering.

Abrasive particles used in the present disclosure can typically be madeusing tools (i.e., molds) cut using precision machining, which provideshigher feature definition than other fabrication alternatives such as,for example, stamping or punching. Examples of sol-gel-derived alphaalumina (i.e., ceramic) abrasive particles can be found in U.S. Pat. No.5,201,916 (Berg); U.S. Pat. No. 5,366,523 (Rowenhorst (Re 35,570)); andU.S. Pat. No. 5,984,988 (Berg). Details concerning such abrasiveparticles and methods for their preparation can be found, for example,in U.S. Pat. No. 8,142,531 (Adefris et al.); U.S. Pat. No. 8,142,891(Culler et al.); and U.S. Pat. No. 8,142,532 (Erickson et al.); and inU. S. Pat. Appl. Publ. Nos. 2012/0227333 (Adefris et al.); 2013/0040537(Schwabel et al.); and 2013/0125477 (Adefris).

Examples of slurry derived alpha alumina abrasive particles can be foundin WO 2014/070468, published on May 8, 2014. Slurry derived particlesmay be formed from a powder precursor, such as alumina oxide powder. Theslurry process may be advantageous for larger particles that can bedifficult to make using sol-gel techniques.

The abrasive particles may undergo a sintering process, such as theprocess described in U.S. patent Ser. No. 10/400,146, issued on Sep. 3,2019, for example. However, other processing techniques are expresslycontemplated.

Ultra-fine grain PSG may also be used in abrasive articles describedherein. Ultra-fine grain PSG can be formed using techniques described inU.S. PAP 2019/0233693, published on Aug. 1, 2019, or in WO 2018023177,published on Dec. 20, 2018, or in WO 2018/207145, published on Nov. 15,2018.

Softer PSG particles, with Mohs hardness' between 2.0 and 5.0, that canbe used for abrasive particles herein, particularly where non-scratchapplications are anticipated, can be made according to methods describedin WO 2019/215539, published on Nov. 14, 2019.

The shaped abrasive particles can have at least one sidewall, which maybe a sloping sidewall. In some embodiments, more than one (for exampletwo or three) sloping sidewall can be present and the slope or angle foreach sloping sidewall may be the same or different. In otherembodiments, the sidewall can be minimized for particles where the firstand the second faces taper to a thin edge or point where they meetinstead of having a sidewall. The sloping sidewall can also be definedby a radius, R (as illustrated in FIG. 5B of US Patent Application No.2010/0151196). The radius, R, can be varied for each of the sidewalls.

Specific examples of shaped particles having a ridge line includeroof-shaped particles, for example particles as illustrated, in FIG. 4Ato 4C of WO 2011/068714. Preferred, roof-shaped particles includeparticles having the shape of a hip roof, or hipped roof (a type of roofwherein any sidewalls facets present slope downwards from the ridge lineto the first side. A hipped roof typically does not include verticalsidewall(s) or facet(s)).

Methods for making shaped abrasive particles having at least one slopingsidewall are for example described in US Patent Application PublicationNo. 2009/0165394.

Shaped abrasive particles can also include a plurality of ridges ontheir surfaces. The plurality of grooves (or ridges) can be formed by aplurality of ridges (or grooves) in the bottom surface of a mold cavitythat have been found to make it easier to remove the precursor shapedabrasive particles from the mold.

Methods for making shaped abrasive particles having grooves on at leastone side are for example described in US Patent Application PublicationNo. 2010/0146867.

The shaped abrasive particles may also have one or more notches on oneof the faces of the abrasive particle, as described in PCT ApplicationSer. No. IB2019/060861, filed on Dec. 16, 2019.

Shaped abrasive particles can have an opening (preferably one extendingor passing through the first and second side). Methods for making shapedabrasive particles having an opening are for example described in USPatent Application Publication No. 2010/0151201 and 2009/0165394.

Shaped abrasive particles can also have at least one recessed (orconcave) face or facet; at least one face or facet which is shapedoutwardly (or convex). Methods for making dish-shaped abrasive particlesare for example described in US Patent Application Publication Nos.2010/0151195 and 2009/0165394. Additionally, shaped abrasive particlesmay also have a multifaceted surface as described in U.S. Pat. No.10,150,900, issued on Dec. 11, 2018.

Shaped abrasive particles can also have at least one fractured surface.Methods for making shaped abrasive particles with at least one fracturedsurface are for example described in US Patent Application PublicationNos. 2009/0169816 and 2009/0165394.

Shaped abrasive particles can also have a cavity. Shaped abrasiveparticles may also include an aperture, such as that described in U.S.Pat. No. 8,142,532, issued on Mar. 27, 2012, herein incorporated byreference.

Shaped abrasive particles can also have a low roundness factor. Methodsfor making shaped abrasive particles with low Roundness Factor are forexample described in US Patent Application Publication No. 2010/0319269.

Shaped abrasive particles may have a second vertex on a second side, asdescribed in U.S. Pat. No. 9,447,311, issued on Sep. 16, 2016. Methodsfor making abrasive particles wherein the second side is a vertex (forexample, dual tapered abrasive particles) or a ridge line (for example,roof shaped particles) are for example described in U.S. PAP2012/022733, published on Sep. 13, 2012.

Shaped abrasive particles may be formed to have sharp tips, such asthose described in U.S. PAP 2019/0233693, published on Aug. 1, 2019, orin U.S. Provisional Application with Ser. No. 62/877,443, filed on Jul.23, 2019.

Shaped abrasive particles may also be formed to include a rake angle,such as those described in WO 2019/207423, published on Oct. 31, 2019,or in WO 2019/207417, published on Oct. 31, 2019, or in PCT ApplicationSer. No. IB 2019/059112, filed on Oct. 24, 2019.

Shaped abrasive particles may also be formed to have a precision shapedportion and a non-shaped portion, such as a crushed portion, asdescribed in U.S. Provisional Patent Application 62/833,865, filed onApr. 15, 2019.

Shaped abrasive particles can also have a combination of one or more ofshape features discussed herein, including a sloping sidewall, a groove,a recess, a facet, a fractured surface, a cavity, more than one vertex,sharp edges, a non-shaped portion, a notch, a rake angle and/or a lowroundness factor.

Additionally, the shaped abrasive particles may be agglomerates ofshaped and/or crushed abrasive particles.

As used herein in referring to triangular abrasive particles, the term“length” refers to the maximum dimension of a triangular abrasiveparticle. “Width” refers to the maximum dimension of the triangularabrasive particle that is perpendicular to the length. The terms“thickness” or “height” refer to the dimension of the triangularabrasive particle that is perpendicular to the length and width. Forabrasive particles with shapes other than triangles, length refers to alongest dimension, and width refers to the maximum dimensionperpendicular to the length, while thickness refers to a dimensionperpendicular to both the length and width.

The shaped abrasive particles may have an elongated shape, such as thatdescribed in U.S. PAP 2019/0106362, published on Apr. 11, 2019, or in WO2019/069157, published on Apr. 11, 2019. The elongate shape may betriangular-prism shaped, rod-shaped, or otherwise including one or morevertices along the perimeter.

The shaped abrasive particles may have a variable cross-sectional areaalong a length of the particle, such as those described in U.S. PAP2019/0249051. For example, the shaped abrasive particles may be dog-boneshaped, or otherwise have a cross sectional area that varies from afirst end to a second end.

The shaped abrasive particles may have a tetrahedron shape, such asthose described in WO 2018/207145, published on Nov. 15, 2018, or thoseof U.S. Pat. No. 9,573,250, issued on Feb. 21, 2017.

The shaped abrasive particles may also have a concave or convex portion,or may be defined as having one or more acute interior angles, such asthose described in U.S. Pat. No. 10,301,518, issued on May 28, 2019.

The shaped abrasive particles may also include shape-on-shape particles,such as a plate on plate shaped particle as described in U.S. Pat. No.8,728,185, issued on May 20, 2014.

The shaped abrasive particles may also include shaped abrasive particlesthat have an irregular polygonal shape, as described in U.S. ProvisionalPatent Application 62/924,956, filed on Oct. 23, 2019.

The shaped abrasive particles may also be shaped to be self-standingabrasive particles, such that cutting portions are more likely to embedin a make coat, for example, in an orientation away from the backing,such as those described in PCT Application with Ser. No. IB 2019/060457,filed on Dec. 4, 2019.

The shaped abrasive particles can also be aggregate particles. Theaggregate particles may include shaped abrasive particles in a vitreousbond matrix as described, for example, in U.S. PAP 2018/081246,published on May 3, 2018. The aggregate particles may also includeshaped abrasive particles in a silicate binder, as described in WO2019/167022, published on Sep. 6, 2019. The aggregate particles may alsoinclude frustro-pyrimidal shaped particles in a vitreous bond matrix, asdescribed in US PAP 2019/0283216, published on Sep. 19, 2019. Theaggregate may also include a mixture of crushed and shaped particles, asdescribed in PCT Publication IB/2019/058349, filed on Oct. 1, 2019.

The abrasive grain may have a surface treatment thereon. In someinstances, the surface treatment may increase adhesion to the binder,alter the abrading characteristics of the abrasive particle, or thelike. Examples of surface treatments include coupling agents, halidesalts, metal oxides including silica, refractory metal nitrides, andrefractory metal carbides.

The abrasive layer may also comprise diluent particles, typically on thesame order of magnitude as the abrasive particles. Examples of suchdiluent particles include gypsum, marble, limestone, flint, silica,glass bubbles, glass beads, and aluminum silicate.

Abrasive articles and vibratory finishing systems described herein maybe suitable for a variety of workpieces having material and may have anyform. Examples of materials include metal, metal alloys, exotic metalalloys, ceramics, painted surfaces, plastics, polymeric coatings, stone,polycrystalline silicon, wood, marble, and combinations thereof.Examples of workpieces include molded and/or shaped articles (e.g.,optical lenses, automotive body panels, boat hulls, counters, andsinks), wafers, sheets, and blocks.

Depending upon the application, the force at the abrading interface canrange from about 0.1 kg to over 1000 kg. Generally, this range isbetween 1 kg to 500 kg of force at the abrading interface. Also,depending upon the application there may be a liquid present duringabrading. This liquid can be water and/or an organic compound. Examplesof typical organic compounds include lubricants, oils, emulsifiedorganic compounds, cutting fluids, surfactants (e.g., soaps,organosulfates, sulfonates, organophosphonates, organophosphates), andcombinations thereof. These liquids may also contain other additivessuch as defoamers, degreasers, corrosion inhibitors, and combinationsthereof.

Objects and advantages of this invention are further illustrated by thefollowing non-limiting examples, but the particular materials andamounts thereof recited in these examples, as well as other conditionsand, details, should not be construed to unduly limit this invention.

An abrading system is presented that includes a first vibratorystructure comprising a first plurality of protrusions, a secondvibratory structure comprising a second plurality of protrusions, anabrasive article contacting the first film, and a stroke plate coupledto the second film. When the stroke plate is activated, the first andsecond plurality of protrusions are configured to interlock and slipwith respect to each other in a first direction.

The abrading system may be implemented such that the abrasive article isa rolled sheet of abrasive fed through the abrading system in a feedingdirection. The feeding direction is perpendicular to the firstdirection.

The abrading system may be implemented such that the abrasive article isa coated abrasive article, a bonded abrasive article or a nonwovenabrasive article.

The abrading system may be implemented such that the abrasive articleincludes abrasive particles. The abrasive particles include crushed,formed, or shaped abrasive particles.

The abrading system may be implemented such that the first plurality ofprotrusions include a shaped protrusion repeating along a surface of thefirst vibratory structure.

The abrading system may be implemented such that the shaped protrusionrepeats along the surface of the first vibratory structure at regularintervals.

The abrading system may be implemented such that the regular intervalsinclude a space length between adjacent protrusions that is greater thana protrusion width.

The abrading system may be implemented such that a sum of the regularinterval and the protrusion width is less than or equal to twice aheight of the shaped protrusion.

The abrading system may be implemented such that the shaped protrusionis a rectangular shaped protrusion.

The abrading system may be implemented such that the shaped protrusionincludes a triangular shaped protrusion.

The abrading system may be implemented such that the shaped protrusionhas a rounded corner.

The abrading system may be implemented such that the first and secondvibratory structures include microreplicated film.

The abrading system may be implemented such that the microreplicatedfilm includes a resin.

The abrading system may be implemented such that the microreplicatedfilm includes a polyolefin.

The abrading system may be implemented such that it includes acompressible pad between the stroke plate and the second vibratorystructure.

A robotic repair system is presented that includes an abrading systemwith a vibration source, a first structure, with a first interlockingfeature, coupled to the vibration source, and a second structure, with asecond interlocking feature interlocked to the first locking feature.The first and second structures are configured to, when interlocked,slip in a first direction. An abrasive article contacts the secondstructure on a second side opposite a first side that contacts the firststructure. The abrading system also includes a robotic repair unitconfigured to move the abrading system into position over a workpieceand a mount that couples the abrading system to the robotic repair unit.

The robotic repair system may be implemented such that the abrasivearticle is an abrasive belt. The abrading system also includes a beltfeeder that feeds the belt in between the second structure and theworkpiece, in a feed direction. The feed direction is different from thefirst direction.

The robotic repair system may be implemented such that the feeddirection is perpendicular to the first direction.

The robotic repair system may be implemented such that, during anabrasive operation, a surface area of the abrasive belt contacts theworkpiece. The surface area of the abrasive article includes a dimensionof the second structure and a width of the abrasive belt.

The robotic repair system may be implemented such that the abrasive beltis fed from a first belt roll to a second belt roll.

The robotic repair system may be implemented such that it also includesa cushion in between the vibration source and the first structure.

The robotic repair system may be implemented such that the vibrationsource is a stroke plate.

The robotic repair system may be implemented such that the abrasivearticle is an abrasive pad coupled to the second structure.

The robotic repair system may be implemented such that the abrasivearticle includes abrasive particles. The abrasive particles includecrushed, formed or shaped abrasive particles.

The robotic repair system may be implemented such that the abrasivearticle is a coated, bonded or nonwoven abrasive article.

The robotic repair system may be implemented such that the first andsecond interlocking features are micro-replicated features.

The robotic repair system may be implemented such that the first andsecond interlocking features each include a plurality of protrusionsextending from a base surface. The robotic repair system may beimplemented such that, when in an interlocking position, a plurality ofspaces are present between the first and second interlocking features.

The robotic repair system may be implemented such that the pluralityprotrusions include a repeating shape.

The robotic repair system may be implemented such that the repeatingshape is rectangular or triangular.

The robotic repair system may be implemented such that the repeatingshape is a polygon adjacent a space.

The robotic repair system may be implemented such that the length of therepeating shape is less than or equal to twice a height of the repeatingshape.

A method of abrading a surface that includes coupling an abrasivearticle to an abrading system. The abrading system includes a vibrationsource and a first structure coupled to the vibration source. The firststructure includes a first plurality of protrusions extending from afirst base. The abrading system also includes a second structurecomprising a second plurality of protrusions, extending from a secondbase. The second plurality of protrusions interlock with the firstplurality of protrusions. The abrasive article is coupled to the secondstructure. The method also includes actuating the abrading system.Actuating the abrading system causes the first and second plurality ofprotrusions to slip with respect to each other in a first direction.

The method may be implemented such that it also includes causing theabrasive article to move with respect to the workpiece in a feeddirection.

The method may be implemented such that the workpiece remainsstationary, the abrasive article is physically attached to the secondstructure, and causing the abrasive article to move includes moving theabrading system using a robotic repair unit.

The method may be implemented such that the workpiece remainsstationary, the abrasive article is an abrasive belt. Causing theabrasive article to move includes feeding the abrasive belt, undertension, from a feed roll to a rolling roll.

The method may be implemented such that a feeding direction is oppositethe first direction. The first and second plurality of protrusionssubstantially prohibit slippage in the feeding direction.

The method may be implemented such that the first plurality ofprotrusions are micro-replicated.

The method may be implemented such that the first plurality ofprotrusions are machined into the first structure.

The method may be implemented such that the first plurality ofprotrusions are formed of the same material as the first base.

The method may be implemented such that the first plurality ofprotrusions are integral to the first base.

The method may be implemented such that the first plurality ofprotrusions have a first protrusion height, the second plurality ofprotrusions have a second protrusion height, and the first and secondprotrusions heights are the same.

The method may be implemented such that the first and second pluralityof protrusions interlock such that gaps are present between adjacentprotrusions.

The method may be implemented such that the first plurality ofprotrusions are polygonal in shape.

The method may be implemented such that the polygonal shape issubstantially rectangular or substantially triangular.

The method may be implemented such that the vibration source is a strokeplate.

The method may be implemented such that a cushion is present between thevibration source and the first structure.

An abrasive article is presented that includes a substrate longer in afirst direction than a second direction. The abrasive article alsoincludes a plurality of protrusions on the substrate. The protrusionsextend in the second direction. The protrusions are in a repeatingpattern on the substrate.

The abrasive article may be implemented such that the substrate has afirst side, comprising the protrusions, and a second side. The secondside includes a plurality of abrasive particles configured to contact awork surface.

The abrasive article may be implemented such that the substrate has afirst side, comprising the protrusions, and a second side. The secondside contacts a cushion.

The abrasive article may be implemented such that the abrasive articleis a coated abrasive article, a bonded abrasive article or a nonwovenabrasive article.

The abrasive article may be implemented such that the abrasive articleincludes abrasive particles. The abrasive particles include crushed,formed, or shaped abrasive particles.

The abrasive article may be implemented such that the repeating patternincludes a space length between adjacent protrusions that is greaterthan a protrusion width.

The abrasive article may be implemented such that a length of a firstedge of a first protrusion and a corresponding first edge of a secondprotrusion is less than or equal to twice a height of the shapedprotrusion.

The abrasive article may be implemented such that abrasive article isrolled around a core.

The abrasive article may be implemented such that the abrasive articleis on the core side.

The abrasive article may be implemented such that the protrusions are onthe core side.

Examples

FIGS. 7A-7C illustrate experimental results discussed in the Examplesherein. An abrasive was obtained from 3M company, model 373L, 30 mic.The abrasive was adhered to microreplicated film as described herein,with dimensions of a+a′=230 μm and b=150 μm. The workpiece was an SUS304. The machine illustrated in FIGS. 5A-5C was used, and the abrasivearticle was handfed through the machine. The pad size was 25 mm×50 mm×10mm in height. A sponge was used as the pad to provide cushion. A load of15.7N was applied.

FIG. 7A illustrates the cut rate comparing a pad as described above,labeled as “Example A” compared to a traditional pad. FIG. 7Billustrates the pad of Example A after a grinding operation withvibratory scratching, while FIG. 7C illustrates the pad of Example Awith feeding scratch only. More abrading is illustrated when thevibrations are observed.

Various modifications and alterations of this invention may be made bythose skilled in the art without departing from the scope and spirit ofthis invention, and it should be understood that this invention is notto be unduly limited to the illustrative embodiments set forth herein.

1. An abrading system comprising: a first vibratory structure comprisinga first plurality of protrusions; a second vibratory structurecomprising a second plurality of protrusions; an abrasive articlecontacting the first plurality of protrusions; a stroke plate coupled tothe second plurality of protrusions; and wherein, when the stroke plateis activated, the first and second plurality of protrusions areconfigured to interlock and slip with respect to each other in a firstdirection.
 2. The abrading system of claim 1, wherein the abrasivearticle is a rolled sheet of abrasive fed through the abrading system ina feeding direction, and wherein the feeding direction is perpendicularto the first direction.
 3. The abrading system of claim 1, wherein theabrasive article is a coated abrasive article, a bonded abrasive articleor a nonwoven abrasive article.
 4. The abrading system of claim 1,wherein the abrasive article comprises abrasive particles, and whereinthe abrasive particles comprise crushed, formed, or shaped abrasiveparticles.
 5. The abrading system of claim 1, wherein the firstplurality of protrusions comprise a shaped protrusion repeating along asurface of the first vibratory structure. 6-11. (canceled)
 12. Theabrading system of claim 1, wherein the first and second vibratorystructures comprise microreplicated film.
 13. (canceled)
 14. (canceled)15. The abrading system of claim 1, and further comprising acompressible pad between the stroke plate and the second vibratorystructure.
 16. A robotic repair system comprising: an abrading systemcomprising: a vibration source; a first structure, with a firstinterlocking feature, coupled to the vibration source; a secondstructure, with a second interlocking feature interlocked to the firstlocking feature; wherein, the first and second structures are configuredto, when interlocked, slip in a first direction; and wherein an abrasivearticle contacts the second structure on a second side opposite a firstside that contacts the first structure; a robotic repair unit configuredto move the abrading system into position over a workpiece; and a mountthat couples the abrading system to the robotic repair unit.
 17. Therobotic repair system of claim 16, wherein the abrasive article is anabrasive belt, and wherein the abrading system also comprises a beltfeeder that feeds the belt in between the second structure and theworkpiece, in a feed direction, and wherein the feed direction isdifferent from the first direction. 18-22. (canceled)
 23. The roboticrepair system of claim 16, wherein the abrasive article is an abrasivepad coupled to the second structure.
 24. (canceled)
 25. (canceled) 26.The robotic repair system of claim 16, wherein the first and secondinterlocking features are micro-replicated features.
 27. The roboticrepair system of claim 16, wherein the first and second interlockingfeatures each comprise a plurality of protrusions extending from a basesurface. 28-32. (canceled)
 33. A method of abrading a surfacecomprising: coupling an abrasive article to an abrading system, whereinthe abrading system comprises: a vibration source; a first structurecoupled to the vibration source, wherein the first structure comprises afirst plurality of protrusions extending from a first base; a secondstructure comprising a second plurality of protrusions, extending from asecond base, wherein the second plurality of protrusions interlock withthe first plurality of protrusions; and wherein the abrasive article iscoupled to the second structure; and actuating the abrading system,wherein actuating the abrading system causes the first and secondplurality of protrusions to slip with respect to each other in a firstdirection.
 34. The method of claim 33, and further comprising: causingthe abrasive article to move with respect to the workpiece in a feeddirection. 35-37. (canceled)
 38. The method of claim 33, wherein thefirst plurality of protrusions are micro-replicated.
 39. The method ofclaim 33 wherein the first plurality of protrusions are machined intothe first structure.
 40. The method of claim 33, wherein the firstplurality of protrusions are formed of the same material as the firstbase.
 41. (canceled)
 42. (canceled)
 43. The method of claim 33, whereinthe first and second plurality of protrusions interlock such that gapsare present between adjacent protrusions.
 44. The method of claim 33,wherein the first plurality of protrusions are polygonal in shape. 45.The method of claim 44, wherein the polygonal shape is substantiallyrectangular or substantially triangular. 46-57. (canceled)